基于CFD的垃圾炉排焚烧炉富氧焚烧技术开发及注氧器的优化设计

发布时间：2018-04-21 00:01

本文选题：垃圾 + 富氧焚烧　；参考：《华中科技大学》2015年硕士论文

【摘要】：垃圾焚烧处理是实现无害化、减量化和资源化的最有效手段之一。随着环境问题的日益凸显,愈发严格的环保标准将会大大限制常规垃圾焚烧技术的发展,因此,开发一种新型洁净高效的垃圾焚烧技术将是垃圾焚烧行业的必然发展趋势。本文基于CFD技术进行了垃圾炉排焚烧炉富氧焚烧技术的开发以及富氧焚烧注氧器的优化设计。首先,通过数值模拟对垃圾焚烧炉在常规空气焚烧、富氧焚烧无烟气再循环、富氧焚烧有烟气再循环三种工况下的重要信息进行预测,结果显示,富氧焚烧有烟气再循环时,可燃气体与氧气混合良好;炉内温度分布均匀,燃烧更完全;焚烧炉内的流场组织较好,采用烟气再循环有效的提高了烟气在炉内的停留时间。其次,应用数值模拟对富氧焚烧垃圾炉排焚烧炉进行局部优化研究,结果表明:在合理范围内,适当提高循环烟气量的比例,调整前后墙循环烟气量的配比和改变前后墙喷嘴角度的布置,均可获得更好的流场分布和燃烧传热效果。再次,应用CFD方法对不同类型的注氧装置的速度场、温度场、浓度场等进行研究,结果表明:环式注氧器达到了很好的混合效果,且阻力压降最小,相比喷管式注氧器和扩压式注氧器两种类型更能满足工程实际需要。最后,研究调节部分结构参数对混合气体温度分布、速度分布和浓度分布等的影响,实现对环式注氧器的结构优化。结果表明:注氧环直径取0.7071D,空气管道长度达到1.4D,注氧环外孔取0.28d,内孔取0.4d时注氧效果最好。
[Abstract]:Incineration is one of the most effective methods to realize harmless, minimization and reuse. With the increasingly prominent environmental problems, more stringent environmental standards will greatly limit the development of conventional MSW incineration technology. Therefore, the development of a new clean and efficient MSW incineration technology will be the inevitable development trend of MSW incineration industry. In this paper, the development of oxygen-enriched incineration technology and the optimization design of oxygen-enriched incinerator for MSW grate incinerator are carried out based on CFD technology. Firstly, the important information of MSW incinerator under conventional air incineration, oxygen-enriched incineration without flue gas recirculation and oxygen-enriched incineration with flue gas recirculation is predicted by numerical simulation. The results show that when oxygen-enriched incineration has flue gas recirculation, The combustible gas is well mixed with oxygen; the temperature distribution in the furnace is uniform and the combustion is more complete; the flow field in the incinerator is well organized and the residence time of the flue gas in the furnace is effectively increased by flue gas recirculation. Secondly, the local optimization of the waste grate incinerator for oxygen-enriched incineration is studied by numerical simulation. The results show that the proportion of circulating flue gas is properly increased within a reasonable range. Better flow field distribution and combustion heat transfer can be obtained by adjusting the ratio of circulating flue gas and changing the arrangement of nozzle angle. Thirdly, the velocity field, temperature field and concentration field of different types of oxygen injection devices are studied by CFD method. The results show that the ring oxygen injector achieves a good mixing effect, and the resistance pressure drop is minimum. Compared with two types of nozzle oxygen injector and diffuser oxygen injector, it can meet the practical engineering needs more. Finally, the effects of adjusting some structural parameters on the temperature distribution, velocity distribution and concentration distribution of the mixed gas are studied to optimize the structure of the annular oxygen injector. The results show that the oxygen injection effect is the best when the diameter of oxygen injection ring is 0.7071D, the length of air pipe is 1.4 D, the outer hole of oxygen injection ring is 0.28 days, and the inner hole is 0.4 days.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X705

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